Nowadays, labeling machines are known which comprise a rotating carousel for supporting pans adapted for the resting of individual containers to be labeled, and also comprising at least one pair of identical labeling assemblies which are arranged consecutively at the peripheral region of the carousel.
Each labeling assembly is associated with a slider slidable on guides between a forward active position, in which the labels taken from a tape wound on reels are applied to the containers, and a retracted position designed to load the labels on the reel of tape.
During the operation of the machine, the labeling assemblies are in the forward position, and while one of the assemblies is performing the application of labels onto the containers, gradually consuming the associated reel of tape, the other assembly is waiting and is provided with an intact reel.
When the reel of the labeling assembly that has performed the application of labels has run out, the assembly that was waiting automatically comes into operation, so as to ensure the continuity of operation of the machine.
This exchange takes place with the help of an operator who brings the slider for supporting the labeling assembly that has finished its reel of tape into the retracted position, mounts a new reel of tape, and brings the assembly into the forward position again.
In this manner, the situation is restored wherein both of the assemblies are situated in the forward position, ready to perform the alternation of operation described above.
Obviously, the rotating carousel is provided with a protective structure that prevents access to the carousel proper during operation.
Since the forward position of each labeling assembly is such that the front part of the assembly is situated beyond the protective structure, on the carousel side, and since the retracted position of the assembly is such that this same front part is outside the protective structure, it implies that the presence is necessary, for each labeling assembly, of means that are capable of preventing intrusions beyond the protective structure when the labeling assembly is in the retracted position, and which are capable of allowing the assembly to pass through when it needs to be brought to the forward active position.
The means available today are not entirely satisfactory.